The two webs come from different supply reels, whereby guide rollers lead the respective web to holding and press-on heads which are spaced from each other, but can move toward each other. These holding heads grip, hold, and press the respective web ends to form a splice. The heads are equipped with suction holes and additionally are tiltable for the application of an adhesive tape or strip. Drives are provided for pressing the holding and press-on heads against each other. A severing knife is so arranged that it is effective in a plane between the guide rollers and the holding and press-on heads.
German Patent Publication (DE) 3,411,398 (Bianchetto et al.) corresponding to U.S. Ser. No. 495,301, filed in the U.S.A. on Apr. 20, 1983, now U.S. Pat. No. 4,455,190 (Bianchetto et al.), discloses such an apparatus for the joining of material webs. When one supply reel becomes empty, the trailing end of the respective web must be connected to the leading end of the web on a replacement reel. The known apparatus comprises an upper slide and a lower slide equipped with guide rollers for the material webs and with hold-down rods carrying holding heads and press-on heads. The holding heads and the press-on heads cooperate for fixing the respective web beginning or web end by means of suction air. These holding and press-on heads are movable toward each other. Additionally, upon displacement of the above mentioned slides, in the press-down direction, the heads are tiltable in such a manner that the web end or web beginning secured to the respective head, can be easily coated by an operator because the web beginning and the web end is easily accessible for the application of an adhesive or of an adhesive strip.
The apparatus according to said German Patent Publication 3,411,398 is easy to operate. However, the known apparatus comprises numerous components cooperating in a complicated manner so that the structural effort and expense is quite substantial with the added disadvantage that the entire system is trouble-prone. For example, the severing knife is arranged in a knife carriage or slide into which the web end must be led before the web end can be severed. During the severing operation, the web end extends at a slant to the severing knife or to the knife stroke. A counter tool cooperating with the severing knife is constructed as brushes which are supposed to assure a clean severing cut having regard to the acute cutting angle. However, such a clean cut is not always assured. Further, the above mentioned substantial structural effort and expense is due to the following features: the arrangement of the holding and press-on heads on respective slides, the required mounting of these heads so that they are additionally tiltable toward each other on the slides, the special arrangement and position of the severing knife with its respective drive in a plane between the two slides, and the additional angular levers and control levers which make the entire system rather trouble-prone,as mentioned.